3 phase milling machine to single phase.
 

Several years ago my dad picked up a milling machine that he thought we really needed. The only problem is it has three phase and we only have single phase service. Has anyone used any inverters or anything to try this already? I was curious what they had and what worked

Bill do you have more data on the 3 phase unit? im assuming its 3 phase 208V that you are currently trying to hook up to single phase 220V. RONK has some nice inverters that i have utilized before. have to keep in mind the 120V controls for the milling maching as well. Just wondering what the base line voltage of the 3 phase unit is. I have sized some of these units before for customers. depending on the amp draw of the unit capacitors may want to be added. but ultimately not knowing the true amperage of the units and voltage hard to determine.

Look up VFD...variable frequency drive. They can take an incoming 220-240V single phase and convert it to 220V-240V 3 phase output. Up to 5 HP I think. You can also hook up a pot (potentiometer) knob and adjust the RPM. Lots of youtube vids on how to do. Old school was to by a rotary phase converter which is not much more than a single phase motor driving a 3 phase set of windings. Turn on the phase converter and then you can start your machine.

I have a teco westing house ac inverter 230/460 volt 3 phase .50-30 HP. Its worked well for over 10 years now and still works well. You cant tap threads into holes because it takes 5 seconds or so to spool to 60 hertzs .May have better inverters on the market now.

There’s also an old school device called a Roto Phase thats been around for decades. The most cost effective way to go and simple to install.
Talk to an electrician that’s worked in motor control and he’ll tell you how to make a converter out of an old three phase motor the same size as your mills motor. Cheapest of cheap.

Bill:

Because we live in the downtown business district in Guthrie, OK, we have three phase here in the house. In fact, my HVAC unit runs on 3 phase.

How does that help you? You can store your machine for free at my place!!

It is a 208 volt. We have a c drives running big motors on our grain system but hated to spend that much on this. Grain system has one 50 hp motor so we get along good there. This will be a huge improvement over our antique drill press that uses channel locks for a vise!